Hi.

Tried searching the forum but nothing else really fit, so here goes.

I'm having a weird problem with my 97 Z24 5 speed....

It's gotten where that the engine will just shut down for no apparent reason. I've been getting about 10-15 mins of perfect running & then an abrupt shut off, like the key was turned off... "Check Engine" light does NOT come on either.

It's not an issue while on the expressway (yet), because it's in gear and at speed & it will refire immediately. If it happens at low speed however, like at an intersection, no amount of cranking will immediately start it. Waiting for about 10 mins & then starting has been working so far. And it will start normally, as if nothing had happened. No rough running or anything else.

It seems to be getting fuel - I could smell it when I pulled a plug to check for spark (had it) & I could hear the fuel pump running. And even though spark was confirmed, I went ahead & replaced the coil packs - No difference.

I was thinking partially plugged fuel filter maybe. It spent about 6 months of not being driven very much and then I took it on a 900 mile Interstate trip - running 70-90 mph all the way. Perhaps I've got some trash clogging up the works? Or could I have simply picked up some nasty gas?

Any suggestions? Any help would be appreciated

Anybody?

OK

Here's some thoughts


1.Fuel filter

2. Fuel pressure regulator


3. Fuel Pump (Least likely)


4. Fuel pump ground?


Alont

IMO it has to do with the fuel pump or the coil packs....but that is just a guess.



PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO

Thanks for the replies - this is driving me nuts.

I know it's not the coil packs - they've been replaced.

I've been letting it run outside to see what the interval is... Runs 10 min, Stops - no crank for 10 min, then will start again & etc.

The strange thing is that it will refire immediately if at highway speeds, just by being in gear & being at speed. But will attempt to die again a few minutes (~ 10) & will die if in gear without sufficient speed (revs) to restart it or if at idle.

Well you could try the fuel filter sounds like its not getting enough gas and dieing. And are you saying that it will run for just 10 mins and die?


My car--->http://www.cardomain.com/ride/2569452

I am leaning towards

1) a bad wire in the ignition switch

2) a bad battery ground wire @ the engine block

3) a fault in the oem theft system

Best of luck.

96 cav wrote:Well you could try the fuel filter sounds like its not getting enough gas and dieing. And are you saying that it will run for just 10 mins and die?

Exactly!

I've already got the new filter, I'll try to replace it after work tomorrow.

If that doesn't do it, it's off to the dealer for a diagnostic.

Well... I attempted to remove fuel filter & the effing quick connect side wouldn't budge - even after I managed to destroy the clip with the proper quick-release tool.

The filter remains firmly in place. So much so that I was able to put everything else back together & restart the car without so much as a friggin' drip.

It most certainly did NOT go as the Hayes & Autozone's procedures & pics outlined...

What now? At least my buddy knows a reputable shop within my Z24's 10 min range, if it comes to that.

On my car... I just cut that quick connect thing out and replaced it w/ some rubber fuel line and a few hose clamps..

That thing is too much of a pain in the ass to mess with...

I did that to my car several years ago w/ no problems or leaks.

I suspected as much - GM probably just made it that way because it saved some time on the production line. Not because a quick release was any better than a couple of hose clamps. Just like the reason that they put the water pump in such a craptastic location.

Where did you cut the hose & put your clamps RedDevil?

There could be a bad map sensor, Or bad Intake sensor. Another problem to check is the Relay switch for the fuel pump? Or Just Crappy GAS!! Or a pluged injector. Another problem to check too is the TEMP'.. It might be overheating.. Or a bad Wire some where. Or a safety kill switch for your fuel pump.. Another thing to check is the fuses.. Make sure there making good connect.. GM has that crappy contact paste they use almost everywhere... ANother thing to check to is the O2 senors. Check to see if the second 02 send wire isn't burnt to the exhaste.

Search around for fuel filter. You aren't the first to have problems changing one on a 3rd gen Z.....

Rob





Sold 2/2/05

Thanks for the ideas... Like I said, I was unable to get the thing off in the 1st place.

I was just wondering about how to lash the whole thing up with hose clamps, if it comes to that.

I appreciate the other (electrical) ideas, but as I said before - I have yet to get a CEL. Most of those would definitely generate one.

Well I managed to get the #@$%ing filter replaced without destroying anything than that freaking black plastic OEM clip - the one that came with the new filter is a comparative model of simplicity...

Unfortunately, it didn't do anything to solve the problem - runs fine for 10-15 mins then shuts off (w/ no CEL) then can be restarted 10-15 mins later.

Unless anyone has some insight, it's off to the dealer Mon, morning...

The Z24 went to the dealer yesterday - they haven't investigated my main prob yet. They found some recall stuff to perform first that I wasn't aware of...

One of which was the ignition switch relay - think that could have something to do with it?

Update - not any of the recall stuff (like I had hoped, see above).

Will post back when the culprit has been found....

no that recall is simply for the starter system. hace u looked into an ignition module? it sounds like the module is getting hot and overloading. mine did in my fire ans was ginving my some issues like this, i smacked the IDI cover and it started. replaced the iggy module and never had a problem with it again

Yeah... that was another one of my theories - some elec. part getting hot & failing, then "coming back to life" when it's allowed to cool.

But wouldn't an ignition module failure throw a code or cause the CEL to come on? Seems like that would be an easy & obvious thing for the dealer to check.

I like Sunfirepower97's theory.

I have seen a Buick have a very intermittant miss-fire, no codes/cel at all and a new ign module fixed the problem

Alont

alont wrote:I like Sunfirepower97's theory.

I have seen a Buick have a very intermittant miss-fire, no codes/cel at all and a new ign module fixed the problem

Alont

Actually, I ended up taking it to the dealer & they found that it was a bad Crankshaft Position Sensor. Seems to run fine now.

Weird how it worked 15 min at a time with no misfiring or CEL... Go figure.

At least it was only a $40 part, as opposed to something truly expensive like a fuel pump or electronic controller.

well its good u found the issue

and about the iggy module throwing a code, no it wont b/c all circuits are still intact, ist just the chips and such in the module cant take the heat and dont function properly. b/c mine never threw a code

Skip Fowler wrote:

alont wrote:I like Sunfirepower97's theory.

I have seen a Buick have a very intermittant miss-fire, no codes/cel at all and a new ign module fixed the problem

Alont

Actually, I ended up taking it to the dealer & they found that it was a bad Crankshaft Position Sensor. Seems to run fine now.

i've seen this sensor being the culprit in quite a few GM cars and not just the j-platform. all the symptoms are as you've described - engine suddenly cuts off usually when you idle, no misfire, no rough idle, it just cuts off the sometimes you'll be able to start the car right away but quite often you won't. if anyone is experiencing this with their GM car the crank sensor should be your first culprit if your fuel system checks out ok.

john smith wrote:

Skip Fowler wrote:

alont wrote:I like Sunfirepower97's theory.

I have seen a Buick have a very intermittant miss-fire, no codes/cel at all and a new ign module fixed the problem

Alont

Actually, I ended up taking it to the dealer & they found that it was a bad Crankshaft Position Sensor. Seems to run fine now.

i've seen this sensor being the culprit in quite a few GM cars and not just the j-platform. all the symptoms are as you've described - engine suddenly cuts off usually when you idle, no misfire, no rough idle, it just cuts off the sometimes you'll be able to start the car right away but quite often you won't. if anyone is experiencing this with their GM car the crank sensor should be your first culprit if your fuel system checks out ok.

Yeah... the dealer mentioned that the fuel system was the 1st thing they checked.

I suspect that when the thing is crapping out, it becomes sensitive to heat & fails at a certain point and then allows a restart after it cools off.

By chance did you recently install a header on your z24? It MIGHT be beacuse of the heat off the header is causing your starter to heat up and shut off. The reason why it doesn't stall on the expressway is because of the constant/forced air flow into the engine bay. Just a quick thought.

dan